gitk: Show local uncommitted changes as a fake commit

If there are local changes in the repository, i.e., git-diff-index HEAD
produces some output, then this optionally displays an extra row in
the graph as a child of the HEAD commit (but with a red circle to
indicate that it's not a real commit).  There is a checkbox in the
preferences window to control whether gitk does this or not.

Clicking on the extra row shows the diffs between the working directory
and the HEAD (using git diff-index -p).  The right-click menu on the
extra row allows the user to generate a patch containing the local diffs,
or to display the diffs between the working directory and any commit.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 284 insertions, 53 deletions

diff --git a/gitk b/gitk
index 21eefc40a..cd231d4b6 100755
--- a/gitk
+++ b/gitk
@@ -83,6 +83,7 @@ proc start_rev_list {view} {
     global startmsecs
     global commfd leftover tclencoding datemode
     global viewargs viewfiles commitidx
+    global lookingforhead showlocalchanges
 
     set startmsecs [clock clicks -milliseconds]
     set commitidx($view) 0
@@ -103,6 +104,7 @@ proc start_rev_list {view} {
     }
     set commfd($view) $fd
     set leftover($view) {}
+    set lookingforhead $showlocalchanges
     fconfigure $fd -blocking 0 -translation lf
     if {$tclencoding != {}} {
 	fconfigure $fd -encoding $tclencoding
@@ -262,7 +264,7 @@ proc chewcommits {view} {
 	set tlimit [expr {[clock clicks -milliseconds] + 50}]
 	set more [layoutmore $tlimit $allread]
 	if {$allread && !$more} {
-	    global displayorder commitidx phase
+	    global displayorder nullid commitidx phase
 	    global numcommits startmsecs
 
 	    if {[info exists pending_select]} {
@@ -386,7 +388,7 @@ proc getcommit {id} {
 
 proc readrefs {} {
     global tagids idtags headids idheads tagcontents
-    global otherrefids idotherrefs mainhead
+    global otherrefids idotherrefs mainhead mainheadid
 
     foreach v {tagids idtags headids idheads otherrefids idotherrefs} {
 	catch {unset $v}
@@ -433,10 +435,14 @@ proc readrefs {} {
     }
     close $refd
     set mainhead {}
+    set mainheadid {}
     catch {
 	set thehead [exec git symbolic-ref HEAD]
 	if {[string match "refs/heads/*" $thehead]} {
 	    set mainhead [string range $thehead 11 end]
+	    if {[info exists headids($mainhead)]} {
+		set mainheadid $headids($mainhead)
+	    }
 	}
     }
 }
@@ -505,7 +511,7 @@ proc makewindow {} {
     global findtype findtypemenu findloc findstring fstring geometry
     global entries sha1entry sha1string sha1but
     global maincursor textcursor curtextcursor
-    global rowctxmenu mergemax wrapcomment
+    global rowctxmenu fakerowmenu mergemax wrapcomment
     global highlight_files gdttype
     global searchstring sstring
     global bgcolor fgcolor bglist fglist diffcolors selectbgcolor
@@ -878,6 +884,17 @@ proc makewindow {} {
     $rowctxmenu add command -label "Cherry-pick this commit" \
 	-command cherrypick
 
+    set fakerowmenu .fakerowmenu
+    menu $fakerowmenu -tearoff 0
+    $fakerowmenu add command -label "Diff this -> selected" \
+	-command {diffvssel 0}
+    $fakerowmenu add command -label "Diff selected -> this" \
+	-command {diffvssel 1}
+    $fakerowmenu add command -label "Make patch" -command mkpatch
+#    $fakerowmenu add command -label "Commit" -command {mkcommit 0}
+#    $fakerowmenu add command -label "Commit all" -command {mkcommit 1}
+#    $fakerowmenu add command -label "Revert local changes" -command revertlocal
+
     set headctxmenu .headctxmenu
     menu $headctxmenu -tearoff 0
     $headctxmenu add command -label "Check out this branch" \
@@ -933,7 +950,7 @@ proc click {w} {
 proc savestuff {w} {
     global canv canv2 canv3 ctext cflist mainfont textfont uifont tabstop
     global stuffsaved findmergefiles maxgraphpct
-    global maxwidth showneartags
+    global maxwidth showneartags showlocalchanges
     global viewname viewfiles viewargs viewperm nextviewnum
     global cmitmode wrapcomment
     global colors bgcolor fgcolor diffcolors selectbgcolor
@@ -952,6 +969,7 @@ proc savestuff {w} {
 	puts $f [list set cmitmode $cmitmode]
 	puts $f [list set wrapcomment $wrapcomment]
 	puts $f [list set showneartags $showneartags]
+	puts $f [list set showlocalchanges $showlocalchanges]
 	puts $f [list set bgcolor $bgcolor]
 	puts $f [list set fgcolor $fgcolor]
 	puts $f [list set colors $colors]
@@ -1746,7 +1764,7 @@ proc showview {n} {
     global curview viewdata viewfiles
     global displayorder parentlist childlist rowidlist rowoffsets
     global colormap rowtextx commitrow nextcolor canvxmax
-    global numcommits rowrangelist commitlisted idrowranges
+    global numcommits rowrangelist commitlisted idrowranges rowchk
     global selectedline currentid canv canvy0
     global matchinglines treediffs
     global pending_select phase
@@ -1832,6 +1850,7 @@ proc showview {n} {
 	set rowlaidout [lindex $v 6]
 	set rowoptim [lindex $v 7]
 	set numcommits [lindex $v 8]
+	catch {unset rowchk}
     }
 
     catch {unset colormap}
@@ -1861,8 +1880,9 @@ proc showview {n} {
     } elseif {$selid ne {}} {
 	set pending_select $selid
     } else {
-	if {$numcommits > 0} {
-	    selectline 0 0
+	set row [expr {[lindex $displayorder 0] eq $nullid}]
+	if {$row < $numcommits} {
+	    selectline $row 0
 	} else {
 	    set selectfirst 1
 	}
@@ -2559,11 +2579,12 @@ proc layoutmore {tmax allread} {
     global rowlaidout rowoptim commitidx numcommits optim_delay
     global uparrowlen curview rowidlist idinlist
 
+    set showlast 0
     set showdelay $optim_delay
     set optdelay [expr {$uparrowlen + 1}]
     while {1} {
 	if {$rowoptim - $showdelay > $numcommits} {
-	    showstuff [expr {$rowoptim - $showdelay}]
+	    showstuff [expr {$rowoptim - $showdelay}] $showlast
 	} elseif {$rowlaidout - $optdelay > $rowoptim} {
 	    set nr [expr {$rowlaidout - $optdelay - $rowoptim}]
 	    if {$nr > 100} {
@@ -2592,6 +2613,7 @@ proc layoutmore {tmax allread} {
 		set rowlaidout $commitidx($curview)
 	    } elseif {$rowoptim == $nrows} {
 		set showdelay 0
+		set showlast 1
 		if {$numcommits == $nrows} {
 		    return 0
 		}
@@ -2605,9 +2627,9 @@ proc layoutmore {tmax allread} {
     }
 }
 
-proc showstuff {canshow} {
+proc showstuff {canshow last} {
     global numcommits commitrow pending_select selectedline curview
-    global displayorder selectfirst
+    global lookingforhead mainheadid displayorder nullid selectfirst
 
     if {$numcommits == 0} {
 	global phase
@@ -2634,10 +2656,74 @@ proc showstuff {canshow} {
 	if {[info exists selectedline] || [info exists pending_select]} {
 	    set selectfirst 0
 	} else {
-	    selectline 0 1
+	    set l [expr {[lindex $displayorder 0] eq $nullid}]
+	    selectline $l 1
 	    set selectfirst 0
 	}
     }
+    if {$lookingforhead && [info exists commitrow($curview,$mainheadid)]
+	&& ($last || $commitrow($curview,$mainheadid) < $numcommits - 1)} {
+	set lookingforhead 0
+	dodiffindex
+    }
+}
+
+proc doshowlocalchanges {} {
+    global lookingforhead curview mainheadid phase commitrow
+
+    if {[info exists commitrow($curview,$mainheadid)] &&
+	($phase eq {} || $commitrow($curview,$mainheadid) < $numcommits - 1)} {
+	dodiffindex
+    } elseif {$phase ne {}} {
+	set lookingforhead 1
+    }
+}
+
+proc dohidelocalchanges {} {
+    global lookingforhead localrow lserial
+
+    set lookingforhead 0
+    if {$localrow >= 0} {
+	removerow $localrow
+	set localrow -1
+    }
+    incr lserial
+}
+
+# spawn off a process to do git diff-index HEAD
+proc dodiffindex {} {
+    global localrow lserial
+
+    incr lserial
+    set localrow -1
+    set fd [open "|git diff-index HEAD" r]
+    fconfigure $fd -blocking 0
+    filerun $fd [list readdiffindex $fd $lserial]
+}
+
+proc readdiffindex {fd serial} {
+    global localrow commitrow mainheadid nullid curview
+    global commitinfo commitdata lserial
+
+    if {[gets $fd line] < 0} {
+	if {[eof $fd]} {
+	    close $fd
+	    return 0
+	}
+	return 1
+    }
+    # we only need to see one line and we don't really care what it says...
+    close $fd
+
+    if {$serial == $lserial && $localrow == -1} {
+	# add the line for the local diff to the graph
+	set localrow $commitrow($curview,$mainheadid)
+	set hl "Local uncommitted changes"
+	set commitinfo($nullid) [list  $hl {} {} {} {} "    $hl\n"]
+	set commitdata($nullid) "\n    $hl\n"
+	insertrow $localrow $nullid
+    }
+    return 0
 }
 
 proc layoutrows {row endrow last} {
@@ -2815,7 +2901,7 @@ proc insert_pad {row col npad} {
 }
 
 proc optimize_rows {row col endrow} {
-    global rowidlist rowoffsets idrowranges displayorder
+    global rowidlist rowoffsets displayorder
 
     for {} {$row < $endrow} {incr row} {
 	set idlist [lindex $rowidlist $row]
@@ -3233,9 +3319,13 @@ proc drawcmittext {id row col} {
     global commitlisted commitinfo rowidlist parentlist
     global rowtextx idpos idtags idheads idotherrefs
     global linehtag linentag linedtag
-    global mainfont canvxmax boldrows boldnamerows fgcolor
+    global mainfont canvxmax boldrows boldnamerows fgcolor nullid
 
-    set ofill [expr {[lindex $commitlisted $row]? "blue": "white"}]
+    if {$id eq $nullid} {
+	set ofill red
+    } else {
+	set ofill [expr {[lindex $commitlisted $row]? "blue": "white"}]
+    }
     set x [xc $row $col]
     set y [yc $row]
     set orad [expr {$linespc / 3}]
@@ -3647,10 +3737,10 @@ proc show_status {msg} {
 # The new commit will be displayed on row $row and the commits
 # on that row and below will move down one row.
 proc insertrow {row newcmit} {
-    global displayorder parentlist childlist commitlisted
+    global displayorder parentlist childlist commitlisted children
     global commitrow curview rowidlist rowoffsets numcommits
     global rowrangelist rowlaidout rowoptim numcommits
-    global selectedline
+    global selectedline rowchk commitidx
 
     if {$row >= $numcommits} {
 	puts "oops, inserting new row $row but only have $numcommits rows"
@@ -3663,12 +3753,14 @@ proc insertrow {row newcmit} {
     lappend kids $newcmit
     lset childlist $row $kids
     set childlist [linsert $childlist $row {}]
+    set children($curview,$p) $kids
     set commitlisted [linsert $commitlisted $row 1]
     set l [llength $displayorder]
     for {set r $row} {$r < $l} {incr r} {
 	set id [lindex $displayorder $r]
 	set commitrow($curview,$id) $r
     }
+    incr commitidx($curview)
 
     set idlist [lindex $rowidlist $row]
     set offs [lindex $rowoffsets $row]
@@ -3704,6 +3796,8 @@ proc insertrow {row newcmit} {
 	lset rowrangelist $rp1 $ranges
     }
 
+    catch {unset rowchk}
+
     incr rowlaidout
     incr rowoptim
     incr numcommits
@@ -3714,6 +3808,67 @@ proc insertrow {row newcmit} {
     redisplay
 }
 
+# Remove a commit that was inserted with insertrow on row $row.
+proc removerow {row} {
+    global displayorder parentlist childlist commitlisted children
+    global commitrow curview rowidlist rowoffsets numcommits
+    global rowrangelist idrowranges rowlaidout rowoptim numcommits
+    global linesegends selectedline rowchk commitidx
+
+    if {$row >= $numcommits} {
+	puts "oops, removing row $row but only have $numcommits rows"
+	return
+    }
+    set rp1 [expr {$row + 1}]
+    set id [lindex $displayorder $row]
+    set p [lindex $parentlist $row]
+    set displayorder [lreplace $displayorder $row $row]
+    set parentlist [lreplace $parentlist $row $row]
+    set childlist [lreplace $childlist $row $row]
+    set commitlisted [lreplace $commitlisted $row $row]
+    set kids [lindex $childlist $row]
+    set i [lsearch -exact $kids $id]
+    if {$i >= 0} {
+	set kids [lreplace $kids $i $i]
+	lset childlist $row $kids
+	set children($curview,$p) $kids
+    }
+    set l [llength $displayorder]
+    for {set r $row} {$r < $l} {incr r} {
+	set id [lindex $displayorder $r]
+	set commitrow($curview,$id) $r
+    }
+    incr commitidx($curview) -1
+
+    set rowidlist [lreplace $rowidlist $row $row]
+    set rowoffsets [lreplace $rowoffsets $rp1 $rp1]
+    if {$kids ne {}} {
+	set offs [lindex $rowoffsets $row]
+	set offs [lreplace $offs end end]
+	lset rowoffsets $row $offs
+    }
+
+    set rowrangelist [lreplace $rowrangelist $row $row]
+    if {[llength $kids] > 0} {
+	set ranges [lindex $rowrangelist $row]
+	if {[lindex $ranges end-1] eq $id} {
+	    set ranges [lreplace $ranges end-1 end]
+	    lset rowrangelist $row $ranges
+	}
+    }
+
+    catch {unset rowchk}
+
+    incr rowlaidout -1
+    incr rowoptim -1
+    incr numcommits -1
+
+    if {[info exists selectedline] && $selectedline > $row} {
+	incr selectedline -1
+    }
+    redisplay
+}
+
 # Don't change the text pane cursor if it is currently the hand cursor,
 # showing that we are over a sha1 ID link.
 proc settextcursor {c} {
@@ -4392,13 +4547,18 @@ proc goforw {} {
 }
 
 proc gettree {id} {
-    global treefilelist treeidlist diffids diffmergeid treepending
+    global treefilelist treeidlist diffids diffmergeid treepending nullid
 
     set diffids $id
     catch {unset diffmergeid}
     if {![info exists treefilelist($id)]} {
 	if {![info exists treepending]} {
-	    if {[catch {set gtf [open [concat | git ls-tree -r $id] r]}]} {
+	    if {$id ne $nullid} {
+		set cmd [concat | git ls-tree -r $id]
+	    } else {
+		set cmd [concat | git ls-files]
+	    }
+	    if {[catch {set gtf [open $cmd r]}]} {
 		return
 	    }
 	    set treepending $id
@@ -4413,18 +4573,22 @@ proc gettree {id} {
 }
 
 proc gettreeline {gtf id} {
-    global treefilelist treeidlist treepending cmitmode diffids
+    global treefilelist treeidlist treepending cmitmode diffids nullid
 
     set nl 0
     while {[incr nl] <= 1000 && [gets $gtf line] >= 0} {
-	set tl [split $line "\t"]
-	if {[lindex $tl 0 1] ne "blob"} continue
-	set sha1 [lindex $tl 0 2]
-	set fname [lindex $tl 1]
-	if {[string index $fname 0] eq "\""} {
-	    set fname [lindex $fname 0]
-	}
-	lappend treeidlist($id) $sha1
+	if {$diffids ne $nullid} {
+	    set tl [split $line "\t"]
+	    if {[lindex $tl 0 1] ne "blob"} continue
+	    set sha1 [lindex $tl 0 2]
+	    set fname [lindex $tl 1]
+	    if {[string index $fname 0] eq "\""} {
+		set fname [lindex $fname 0]
+	    }
+	    lappend treeidlist($id) $sha1
+	} else {
+	    set fname $line
+	}
 	lappend treefilelist($id) $fname
     }
     if {![eof $gtf]} {
@@ -4445,7 +4609,7 @@ proc gettreeline {gtf id} {
 }
 
 proc showfile {f} {
-    global treefilelist treeidlist diffids
+    global treefilelist treeidlist diffids nullid
     global ctext commentend
 
     set i [lsearch -exact $treefilelist($diffids) $f]
@@ -4453,10 +4617,17 @@ proc showfile {f} {
 	puts "oops, $f not in list for id $diffids"
 	return
     }
-    set blob [lindex $treeidlist($diffids) $i]
-    if {[catch {set bf [open [concat | git cat-file blob $blob] r]} err]} {
-	puts "oops, error reading blob $blob: $err"
-	return
+    if {$diffids ne $nullid} {
+	set blob [lindex $treeidlist($diffids) $i]
+	if {[catch {set bf [open [concat | git cat-file blob $blob] r]} err]} {
+	    puts "oops, error reading blob $blob: $err"
+	    return
+	}
+    } else {
+	if {[catch {set bf [open $f r]} err]} {
+	    puts "oops, can't read $f: $err"
+	    return
+	}
     }
     fconfigure $bf -blocking 0
     filerun $bf [list getblobline $bf $diffids]
@@ -4582,11 +4753,11 @@ proc getmergediffline {mdf id np} {
 }
 
 proc startdiff {ids} {
-    global treediffs diffids treepending diffmergeid
+    global treediffs diffids treepending diffmergeid nullid
 
     set diffids $ids
     catch {unset diffmergeid}
-    if {![info exists treediffs($ids)]} {
+    if {![info exists treediffs($ids)] || [lsearch -exact $ids $nullid] >= 0} {
 	if {![info exists treepending]} {
 	    gettreediffs $ids
 	}
@@ -4601,13 +4772,33 @@ proc addtocflist {ids} {
     getblobdiffs $ids
 }
 
+proc diffcmd {ids flags} {
+    global nullid
+
+    set i [lsearch -exact $ids $nullid]
+    if {$i >= 0} {
+	set cmd [concat | git diff-index $flags]
+	if {[llength $ids] > 1} {
+	    if {$i == 0} {
+		lappend cmd -R [lindex $ids 1]
+	    } else {
+		lappend cmd [lindex $ids 0]
+	    }
+	} else {
+	    lappend cmd HEAD
+	}
+    } else {
+	set cmd [concat | git diff-tree --no-commit-id -r $flags $ids]
+    }
+    return $cmd
+}
+
 proc gettreediffs {ids} {
     global treediff treepending
+
     set treepending $ids
     set treediff {}
-    if {[catch \
-	 {set gdtf [open [concat | git diff-tree --no-commit-id -r $ids] r]} \
-	]} return
+    if {[catch {set gdtf [open [diffcmd $ids {}] r]}]} return
     fconfigure $gdtf -blocking 0
     filerun $gdtf [list gettreediffline $gdtf $ids]
 }
@@ -4644,8 +4835,7 @@ proc getblobdiffs {ids} {
     global diffinhdr treediffs
 
     set env(GIT_DIFF_OPTS) $diffopts
-    set cmd [concat | git diff-tree --no-commit-id -r -p -C $ids]
-    if {[catch {set bdf [open $cmd r]} err]} {
+    if {[catch {set bdf [open [diffcmd $ids {-p -C}] r]} err]} {
 	puts "error getting diffs: $err"
 	return
     }
@@ -5207,19 +5397,25 @@ proc mstime {} {
 }
 
 proc rowmenu {x y id} {
-    global rowctxmenu commitrow selectedline rowmenuid curview
+    global rowctxmenu commitrow selectedline rowmenuid curview nullid
+    global fakerowmenu
 
+    set rowmenuid $id
     if {![info exists selectedline]
 	|| $commitrow($curview,$id) eq $selectedline} {
 	set state disabled
     } else {
 	set state normal
     }
-    $rowctxmenu entryconfigure "Diff this*" -state $state
-    $rowctxmenu entryconfigure "Diff selected*" -state $state
-    $rowctxmenu entryconfigure "Make patch" -state $state
-    set rowmenuid $id
-    tk_popup $rowctxmenu $x $y
+    if {$id ne $nullid} {
+	set menu $rowctxmenu
+    } else {
+	set menu $fakerowmenu
+    }
+    $menu entryconfigure "Diff this*" -state $state
+    $menu entryconfigure "Diff selected*" -state $state
+    $menu entryconfigure "Make patch" -state $state
+    tk_popup $menu $x $y
 }
 
 proc diffvssel {dirn} {
@@ -5330,12 +5526,20 @@ proc mkpatchrev {} {
 }
 
 proc mkpatchgo {} {
-    global patchtop
+    global patchtop nullid
 
     set oldid [$patchtop.fromsha1 get]
     set newid [$patchtop.tosha1 get]
     set fname [$patchtop.fname get]
-    if {[catch {exec git diff-tree -p $oldid $newid >$fname &} err]} {
+    if {$newid eq $nullid} {
+	set cmd [list git diff-index -p $oldid]
+    } elseif {$oldid eq $nullid} {
+	set cmd [list git diff-index -p -R $newid]
+    } else {
+	set cmd [list git diff-tree -p $oldid $newid]
+    }
+    lappend cmd >$fname &
+    if {[catch {eval exec $cmd} err]} {
 	error_popup "Error creating patch: $err"
     }
     catch {destroy $patchtop}
@@ -5608,11 +5812,13 @@ proc headmenu {x y id head} {
 
 proc cobranch {} {
     global headmenuid headmenuhead mainhead headids
+    global showlocalchanges mainheadid
 
     # check the tree is clean first??
     set oldmainhead $mainhead
     nowbusy checkout
     update
+    dohidelocalchanges
     if {[catch {
 	exec git checkout -q $headmenuhead
     } err]} {
@@ -5621,10 +5827,14 @@ proc cobranch {} {
     } else {
 	notbusy checkout
 	set mainhead $headmenuhead
+	set mainheadid $headmenuid
 	if {[info exists headids($oldmainhead)]} {
 	    redrawtags $headids($oldmainhead)
 	}
 	redrawtags $headmenuid
+	if {$showlocalchanges} {
+	    dodiffindex
+	}
     }
 }
 
@@ -6594,7 +6804,7 @@ proc doquit {} {
 
 proc doprefs {} {
     global maxwidth maxgraphpct diffopts
-    global oldprefs prefstop showneartags
+    global oldprefs prefstop showneartags showlocalchanges
     global bgcolor fgcolor ctext diffcolors selectbgcolor
     global uifont tabstop
 
@@ -6604,7 +6814,7 @@ proc doprefs {} {
 	raise $top
 	return
     }
-    foreach v {maxwidth maxgraphpct diffopts showneartags} {
+    foreach v {maxwidth maxgraphpct diffopts showneartags showlocalchanges} {
 	set oldprefs($v) [set $v]
     }
     toplevel $top
@@ -6621,6 +6831,11 @@ proc doprefs {} {
 	-font optionfont
     spinbox $top.maxpct -from 1 -to 100 -width 4 -textvariable maxgraphpct
     grid x $top.maxpctl $top.maxpct -sticky w
+    frame $top.showlocal
+    label $top.showlocal.l -text "Show local changes" -font optionfont
+    checkbutton $top.showlocal.b -variable showlocalchanges
+    pack $top.showlocal.b $top.showlocal.l -side left
+    grid x $top.showlocal -sticky w
 
     label $top.ddisp -text "Diff display options"
     $top.ddisp configure -font $uifont
@@ -6723,9 +6938,9 @@ proc setfg {c} {
 
 proc prefscan {} {
     global maxwidth maxgraphpct diffopts
-    global oldprefs prefstop showneartags
+    global oldprefs prefstop showneartags showlocalchanges
 
-    foreach v {maxwidth maxgraphpct diffopts showneartags} {
+    foreach v {maxwidth maxgraphpct diffopts showneartags showlocalchanges} {
 	set $v $oldprefs($v)
     }
     catch {destroy $prefstop}
@@ -6734,12 +6949,19 @@ proc prefscan {} {
 
 proc prefsok {} {
     global maxwidth maxgraphpct
-    global oldprefs prefstop showneartags
+    global oldprefs prefstop showneartags showlocalchanges
     global charspc ctext tabstop
 
     catch {destroy $prefstop}
     unset prefstop
     $ctext configure -tabs "[expr {$tabstop * $charspc}]"
+    if {$showlocalchanges != $oldprefs(showlocalchanges)} {
+	if {$showlocalchanges} {
+	    doshowlocalchanges
+	} else {
+	    dohidelocalchanges
+	}
+    }
     if {$maxwidth != $oldprefs(maxwidth)
 	|| $maxgraphpct != $oldprefs(maxgraphpct)} {
 	redisplay
@@ -6749,7 +6971,10 @@ proc prefsok {} {
 }
 
 proc formatdate {d} {
-    return [clock format $d -format "%Y-%m-%d %H:%M:%S"]
+    if {$d ne {}} {
+	set d [clock format $d -format "%Y-%m-%d %H:%M:%S"]
+    }
+    return $d
 }
 
 # This list of encoding names and aliases is distilled from
@@ -7059,6 +7284,7 @@ set wrapcomment "none"
 set showneartags 1
 set maxrefs 20
 set maxlinelen 200
+set showlocalchanges 1
 
 set colors {green red blue magenta darkgrey brown orange}
 set bgcolor white
@@ -7111,6 +7337,8 @@ if {$i >= 0} {
     }
 }
 
+set nullid "0000000000000000000000000000000000000000"
+
 set runq {}
 set history {}
 set historyindex 0
@@ -7136,6 +7364,9 @@ set cmdlineok 0
 set stopped 0
 set stuffsaved 0
 set patchnum 0
+set lookingforhead 0
+set localrow -1
+set lserial 0
 setcoords
 makewindow
 wm title . "[file tail $argv0]: [file tail [pwd]]"